During the drilling of a well, drilling fluid is pumped down a hollow drill string and through the drill bit attached thereon. The drill string consists of a plurality of joined sections of pipe. The drilling fluid is pumped down the drill string using a device known as a “Kelly”. The Kelly is attached to the top of the drill string and is a connected to a source of pressurized drilling fluid via a hose. The Kelly is configured to allow the drill string to rotate when drilling the well while the hose remains generally stationary. Pressurized drilling fluid is, thus, pumped through Kelly into the drill string during drilling operations.
The drilling fluid serves to carry cuttings produced by the drill bit to the surface in the space between the drill string and the walls of the well hole being drilled. This space is often referred to as the “annulus”. The drilling fluid also creates a hydrostatic pressure in the annulus that prevents produced substances from blowing out of the well.
The process of removing the drill string from the well consists of raising the drill string out of the well and disconnecting one or more sections of joined pipe from the drill string. This process is often referred to as “tripping out”. Before the pipe sections are removed, the Kelly is removed from the drill string. A Kelly and its associated hose can contain approximately 20 gallons of drilling fluid that is under considerable pressure. The sections of pipe being tripped out also contain drilling fluid inside. When the Kelly or a pipe section is disconnected from the drill string, the drilling fluid in the Kelly or the pipe section spills out uncontrollably over the drilling rig floor and the personnel drilling the well. This results in an unsafe and hazardous environment for the personnel to work in.
It is, therefore, desirable to provide an apparatus that prevents the spilling of drilling fluid on the drilling rig floor when the Kelly or when sections of pipe in a drill string are disconnected.